Turk Kardiyoloji Dernegi Arsivi, cilt.31, sa.9, ss.482-488, 2003 (SCI-Expanded)
Chronic atrial stretch and rheumatic inflammatory activity leads to atrial dilatation, conduction slowing, and this increases the susceptibility to atrial fibrillation (AF). The aim of this study was to examine the effects of changes in the chronic atrial stretch on atrial refractoriness in early period after percutaneous mitral balloon commissurotomy (PMBC) in patients with mitral stenosis and sinus rhythm. We evaluated the changes in pulmonary arterial pressure (PAP), left atrial (LA) pressure, right atrial (RA) pressure, mean mitral diastolic gradient and mitral valve area beside changes in atrial effective refractory periods (AERPs), AERP dispersion, intra- and interatrial conduction times after PBMC in 25 patients. The following hemodynamic parameters were decreased after PBMV mean diastolic gradient (14.5 ±2.6 - 2.8 1.3 mmHg, p<0.001), PAP (53.1 ±12.6 - 35.7 ±8.9 mmHg, p<0.001), mean RA pressure (6.2 ±1.0 - 4.9 ±0.4 mmHg; p=0.03), and LA pressure (25.7 ±4.3 - 12.5 ±2.6 mmHg, p<0.001) and LA diameter (6.2 ±1.0 - 4.9 ±0.4, p=0.03). High right atrial (HRA), distal coronary sinus (DCS) and right posterolateal (RPL) AERP's were increased (216 ±15.0 - 251.1 ±17.1; 266.7 ±17.5 - 269.5 ±24. 8; 207.6 ±20.4 - 259.2 ±20.7 msec) (p<0.001) and AERP dispersion (55.2 ±5.5 - 21.5 ±4.7 msec, p<0.001), PAHIS (52.7 ±5.9 - 39.1 ±4.2 msec, p<0.001) and HRA-DCS interval (65.5 ±14.8 - 47.5 ±12.9, p<0.001) were significantly decreased. Linear regression and correlation analyses revealed that only the changes in AERP dispersion was correlated with changes in LA pressure. Conclusion: Relief of chronic atrial stretch results in an increase in AERPs and decrease in AERP dispersion suggesting the potential reversibility of the electrophysiological features of chronic atrial dilatation. Beside the hemodynamic changes, the decrease in sympathetic activity after PMBC may also affect the atrial conduction properties and vulnerability.